Machine for making paper flower pots



Jan. 7, 1958 J. A. KIRK 2,818,788 MACHINE FOR MAKING PAPER FLOWER POTS 4 Sheets-Sheet 1 J. A. KIRK MACHINE FOR MAKING PAPER FLOWER POTS K Jan. 7, 1958 4 Sheets-Sheet 2 Filed Aug. 16, 1955 dwzar Jan. 7, 1958 J. A. KIRK 2,818,788

MACHINE FOR MAKING PAPER FLOWER POTS Filed Aug. 16, 1955 4 Sheets-Sheet 3 W W, am,

Jan. 7, 1958 J. A. KIRK 2,818,788

MACHINE FOR MAKING PAPER FLOWER POTS Filed Aug. 16, 1955 4 Sheets-Sheet 4 MACHINE FUR MAKING PAPER FLOWER PGTS James A. Kirk, East Walpole, Mass.

Application August 16, 1955, Serial No. 528,685

11 Claims. (Cl. 93-362) This invention relates to a machine for operating on a preformed paper blank by rolling it into a frusto-conical shape to form the side walls of a pot, folding in a disk and a series of fingers along one edge of the blank to form the bottom of the pot, and forming locking tabs in the side walls to prevent the wall of the pot from unrolling.

For some time past it has been customary to make paper flower pots by manually rolling an arcuate strip of heavy paper into the conventional frusto-conical form of a flower pot, the strip having along its concave edge a series of "fingers to be folded upon each other after the strip has been rolled. The fingers overlap one another and form the bottom of the pot. The manipulation of the blanks to form them into pots requires considerable skill and experience, and the problem of providing suitable means for fastening the end of the strip after it has been rolled has been bathing.

According to the present invention a machine is provided to perform the complete operation of making flower pots from preformed strips or blanks and securing the end of each strip without the use of any extraneous fastening means such as clips or staples, the use of metal in flower pots being objectionable.

The machine, which is hereinafter described in detail, comprises chiefly two truncated cones, one of which serves as a core about which the blank is wrapped, the other cone being of larger diameter. The two cones are supported to act as rolls to receive successive blanks in the nip thereof. -By mechanism located mostly in the rolls the leading end of a blank is gripped so that the blank is held as it wraps itself around the smaller roll, a tongue at the trailing end of the blank is thrust through a cut made in the wall of the formed pot, locking tabs are formed in the side wall and are interlocked, and the fingers along the concave edge of the blank are folded successively against the end of the smaller roll the last three or four fingers being tucked in under the others to secure the bottom formation. Upon completion the pot is promptly ejected from the roll on which it was formed.

On the drawings,

Figure l is a side elevation of a machine embodying the invention;

Figure 2 is a front elevation of the same;

Figure 3 is a section on the line 33 of Figure 1;

Figure 4 is a section on the line 44 of Figure 1, on an enlarged scale;

Figure 5 is a section on the line 55 of Figure 1, on an enlarged scale;

Figure 6 is a section on the line 6-6 of Figure 1, on an enlarged scale;

Figure 7 is a fragmentary plan view of a feeding table for directing blanks to the nip of the rolls;

Figures 8 and 9 are fragmentary sectional views on the same plane as Figure 6, but showing the parts in different positions of operation;

Figure 10 is a fragmentary elevation like Figure 3 2,818,788 Patented Jan. 7, 1958 but on an enlarged scale, showing the parts in a different position of operation;

Figure 11 is a plan view of the lower conical roll;

Figure 12 is a face view of a cutting element used in the machine;

Figure 13 is a contour of a blank for a flower pot;

Figure 14 is a perspective view of the blank in an initial stage of forming;

Figure 15 is a perspective view of the blank at a later stage of forming;

Figure 16 is a bottom plan View of a finished cup or flower-pot; and

Figure 17 is a perspective view of the same.

The mechanism shown on the drawings may conveniently be mounted on a bench or table 20. As shown, a standard 22 is secured to the bench, this standard having two bearings 24 and 26, one above the other, for shafts 28 and 30, respectively, the bearings being arranged so that the axes of the shafts converge to a common point of intersection beyond the ends of the shafts. On the convergent end portion of the shaft 28 is mounted a frusto-conical roll 32 which is tangent to a frustoconical roll 34 mounted on the convergent end of the shaft 36. Since the rolls are mutually tangent, their apices are at the point of intersection of the shaft axes.

The function of the machine is to operate on a blank of heavy paper or equivalent sheet material presented to the nip of the rolls 32 and 34 so as to make the blank into a cup or container of frusto-conical shape which can be used as a flower pot. A blank 36 for this purpose is shown in Figure 13. This blank consists primarily of a sector of an annulus adapted to be rolled up into the form of a frustum of a cone fitting on the roll 32. The leading end 38 is the one which is presented to the rolls. The trailing end portion 40 overlaps the leading end on the roll 32 and may have an extension tapered to form a narrow tongue 42 projecting therefrom to be tucked into a slit in the wall of the container as hereinafter described. To provide the container with a bottom, the blank 36 has a disk 44 and a series of curved fingers 46, 43, 50, 52, 54, 56, and 58 projecting from the concave edge of the annulus. These elements are folded from the plane of the blank to bear against the end of the roll 32, the elements being folded in succession as the body of the blank is passing through the nip of the rolls, and overlapping one another to form the bottom of the cup as hereinafter described.

The rolls 32 and 34 are of unequal size, the diameter of the smaller roll 32 at any of the points of tangency being half that of the larger roll 34 at the same point. The rolls are operatively connected together to be driven at equal peripheral speeds so that there is no slippage between the surfaces of the rolls at the line of tangency. This means that the rate of rotation of the smaller roll is just twice that of the larger roll. To keep the rolls in step, bevel gear wheels 62 and 64 are mounted respectively on the shafts 28 and 30 to rotate with the corresponding rolls 32 and 34. The gear Wheel 62 has half the number of teeth of the gear wheel 64 and the wheels are always in mesh so that the smaller roll 32 makes two revolutions for each revolution of the larger roll 34. The rolls are constantly driven by any suitable means such as a pulley 66 on the shaft 30 on which is a power belt 68 connecting it to a suitable source of power.

The roll 32 is provided with gripping means for seizing the leading end 38 of a blank presented to the nip of the rolls and holding on to this end until the blank has been wrapped around the roll to form the cup wall and its other end has been secured to prevent unrolling of the blank. The gripping means comprises one or more bars 70 which extend transversely through the roll 32, two such bars being indicated in Figure 1. These bars are longitudinally slidable in the roll and each has some gear teeth 72 on one side meshing with a long pinion 7 located within the roll 32 and mounted on a shaft 76 whlch projects from the base of the roll. At one end of each bar 70 is a gripper jaw 78 which cooperates with a plate 80, a portion of which is set in flush with the surface of the roll 32, another portion of the plate 80 being bent inward as at 82 (Figure 4) so that when the jaws '78 are i moved inward to grip the end of a blank against the plate 80, the jaws 78 will project little if any beyond the contour of the roll. To move the jaws '78 inward from their extended position (shown in dotted lines in Figure 4) to their retracted gripping position, a shoe 84 is embeded in the larger roll 34 adjacent to a recess 86 in the roll. The rolls are angularly related in such a way that when the jaws 78 approach the nip of the rolls in their extended position (which occurs in every other revolution of the smaller roll 32), they enter the recess 86 and are then pushed to their retracted position by the beveled leading edge of the shoe 84 as the jaws and shoe move into the nip of the revolving rolls. If the leading edge 38 of a paper blank is thrust between the plate 80 and the jaws 78 as the latter approach the nip of the rolls, the end of the blank is thereupon gripped, and the blank is drawn through the nip to be wrapped around the roll 32.

To maintain the jaws in their retracted position until the cup is ready to be discharged from the roll 32, a pinion 88 is mounted on the end of the shaft 76 which projects from the base of the roll 32. A detent or click element 90 is held yieldingly against this pinion by a spring 92 which carries it. The detent g0 enters either of two spaced notches 94 and 96, to hold the jaws 78 in their extended position, when the detent is in the notch 96 (Figure or in their retracted or gripping position, when the detent is in the notch 94 (Figure 4). Some of the teeth of the pinion 88 mesh with a rack 98 on a cam member 106 which is pivoted at 162 and is rocked inward by a roller 104 on the roll 34 at the proper moment to rotate the shaft 76 sufiiciently to project the jaws 78 to their releasing position.

To facilitate the feeding of successive blanks to the nip of the rolls, a table 106 with a suitably arcuate contour (Figure 7) may be mounted on suitable supports 168. Along the convex edge of the table is a guide rail 110. A bar 112 extending across and above the table 166 supports a series of guide rods 114. which extend close to the nip of the rolls and are just enough above the surface of the table to permit a paper blank on the table to slide easily under them to the nip of the rolls. As indicated in Figure 2, the plane of the table 196 is at an angle to the plane of tangency of the two rolls such that when a blank approaches near to the nip of the rolls it is initially bent in a direction opposite to the direction of bend when it is wrapped around the roll 32. During the initial bending of the blank, the disk 44 and fingers 45-6 etc. are successively folded upward and are separated during the initial bend of the body of the blank so that they do not get tangled but overlap each other in proper order when the body of the blank is curled the other way around the roll 32.

To fold the disk 4 and the fingers which follow it, a series of blades 116, 118, 120, 3.22, 124, 126, 128 and 130 are mounted on the small end of the larger roll 34 and project outward from half of the periphery of this end of the roll. As the blank proceeds through the nip of the rolls, the blades in succession engage the respective disk 44 and fingers and fold them approximately to the plane of the end 61) of the small roll 32. The disk 4-4, which is the first element to be folded by the blades, is partly overlapped by the finger 46 which in turn is partly overlapped by the finger 48, the areas of overlap increasing as the adjacent portion of the body of the blank is curled around the roll 32. The disk 44 is not a complete circle but is cut away on one side to provide a wider base for the first finger 46. As a result of the widening of the base of the finger 46, the fourth finger 52 when it passes the nip of the rolls not only laps the trailing edge of the previous finger 56 but also laps the leading edge of the base portion of the first finger 46. In order to make the tip of the finger 52 underlap part of the finger 46, the blade 124 and the blades 126, 128 and 136 which follow it are set at a smaller angle to the end face of the roll 34- so that they impress a greater angle of fold on the fingers against which they press. The tips of all of these fingers are thus tucked behind a portion of the first finger 46 as indicated in Figures 15 and 16. The fingers are thus interlocked to form a bottom for the cup in which the fingers hold one another in place.

To prevent the body of the cup from unrolling when the cup is removed from the roll 32, the ends must be secured together. For this purpose the larger roll 34 is provided with a punch adapted to cut through the overlapping end portion of the body of the blank to form tabs which interlock when the cup is removed from the roll. A punch 140 is mounted on the head 14-2 of a plunger 144 which extends transversely through the larger roll 34 in a direction perpendicular to one of the slant height elements of the roll, so that the other end of the plunger emerges through the base of the roll and carries a cam follower 146 (Figure l) for the actuation of the plunger. The punch 140 is designed to cut a tongue in each of the overlapping portions of the blank on the roll 32. As shown, the punch 140 is cylindrical, the end face being inclined to the axis so that when the punch is projected into a recess 148 in the roll 32 the correct distance, it makes an approximately semicircular cut in each of the overlapping portions of the blank which has been wrapped around the roll 32 by the rotation of the rolls. These cuts form a tab 150 in the outer layer of the blank and a tab 152 in the inner layer, both tabs being pushed into recess 148 so as to be within the contour of the roll 32 (Figures 8 and 9). When the paper cup is later removed from the roll 32 and tends to open out, the tab 150 will catch inside the adjacent overlapped portion of the blank to lock the ends against any further opening or unrolling action.

The plunger head 142 also carries a lance 154 which projects from the lateral surface of the roll 34 when the punch 140 is projected, but at a point spaced from the punch. The end of the lance is sharpened and pointed (Figure 12) so as to pierce the body of the blank at a point 156 where it overlies a recess 158 in the smaller roll 32. The lance 154 also bends the terminal tongue 42 of the blank up as the tongue nears the nip of the rolls, the adjacent portions of the blank being held down by the guide rods 114. When the lance 154 cuts a slit in the wall of the paper cup at 156, it thrusts the tongue 42 through the slit to keep the trailing end of the blank from sticking out tangentially beyond the locking tab 150. This completes the formation of the cup, and the plunger 144 is then moved by springs 16% to retract the lance 154 inside the contour of the roll 34 To project the punch 14th and lance 154 from the roll 34 a fixed cam 162 is mounted on the bench 20 to be engaged by the roller 146 just before the roll 34 completes each revolution.

The operation of the mechanism is as follows. Successive blanks 36 are fed along the table 106 to the nip of the rolls manually or by :any suitable feeding mechanism such as driven rolls 164, 166 conventionally indicated in Figure 2. Each blank as it approaches the rolls is guided by the rail 11th and the guide rods 114 under which it passes. The rolls are rotated constantly and the feeding of the blank is timed so that its leading edge 38 reaches the nip of the rolls just as the extended gripper jaws 78 enter the recess in the roll 34. The jaws are then pushed to the gripping position, the shaft 76 being rotated thereby through a small angle, springing the click 90 out of the notch 96 in the pinion 88. The click 90 enters the notch 94 (Figure 5) to hold the gripper jaws in their retracted position, gripping the leading end of the blank which is thereupon carried around the roll 32 as it rotates. During the first revolution of the roll 32 in a cycle of operations the major portion of the body of the blank is wrapped completely around the roll 32 and the disk 44 and the fingers which follow it are successively folded against the end of the roll 32 by the blades on the end of the roll 34, the last four fingers being tucked under the first finger 46 as well as partially overlapping the preceding finger, as indicated in Figures and 16. As the roll 32 starts on its second revolution and the trailing portion 40 of the blank begins to overlap the leading portion on the roll 32, the cam follower 146 reaches the cam 162 and pushes the plunger 144 to project the punch 40 and the lance outward. The punch makes the locking tab 150 and pushes it through the inner layer of the cup wall. The lance cuts a slit and tucks the tongue 42 of the blank through the slit. The roller 146 rides off the cam 162 allowing the punch and lance to be retracted by the springs 160. Thereupon the roller 1% engages the cam 100 (Figure 10) and rocks it to project the jaws 78 to their open position releasing the leading edge 38 of the blank which has just been made into a cup. The cup is then stripped from the roll 32 by any suitable means such :as an air blast through a hole 180 extending through the roll 32 and shaft 28. The blast may be controlled by a valve 182 in a supply line 184, the valve being actuated at the desired moment by a cam 186 mounted on the shaft so that it operates once for every revolution of the roll 34, that is, for every two revolutions of the smaller roll 32. The roll 32 and the gripper jaws 78 are then ready to receive the next blank from the table 106.

I claim:

1. A machine for making a frusto-conical cup from a one-piece paper blank in the form of a sector of an annulus with a disk and a series of curved fingers extending from the concave edge of the sector, said machine comprising a base, two frusto-conical rolls rotatably mounted on said base in mutual tangency, one of said rolls having a portion with dimensions equal to the dimensions of the cup to be formed from said blank, means for rotating said rolls at equal peripheral speeds, means carried by said one roll for gripping the leading end of a blank presented to the nip of the rolls, whereby the blank is wrapped around said one roll as the rolls rotate, means on the other said roll for successively folding said disk and fingers into a common plane as the blank is fed between the rolls, and means on said other roll for fastening together the end portions of a blank after it has been wrapped around said one roll, said other roll having means for operating said gripping means to grip the end of a blank and to release the blank after the ends thereof have been fastened together.

2. A machine as in claim 1 for operating on a paper blank having a tongue projecting from the trailing end, and means carried by said other roll for cutting a slit in said blank as it is being wrapped about said one roll and tucking said tongue through said slit.

3. A machine as in claim 2, and pneumatic means for ejecting the paper cup from said one roll after said tongue has been tucked in the slit and the gripping means has been released.

4. A machine as in claim 2, said fastening means and slit-cutting means comprising a plunger extending transversely through said other roll, a punch and a lance mounted on said plunger at one end thereof and arranged to be projected from the surface of said other roll by said plunger, a cam follower mounted on the other end of said plunger and projecting from the large end of said other roll, and a fixed cam mounted on said base and engageable by said cam follower each time said other roll revolves to project said punch and lance from the surface of said other roll.

5. A machine for rolling paper blanks into frustoconical cups, each said blank being a sector of an annulus with a disk and a series of curved fingers extending from the concave edge of the sector, said machine comprising a base, two :frusto-conical rolls of unequal size rotatably supported on said base tangent to each other with their axes intersecting, the diameter of the smaller roll at any of the points of mutual contact being equal to one half the diameter of the larger roll at the same point, means for rotating said rolls at equal peripheral speeds whereby the smaller roll revolves twice for each revolution of the larger roll, means carried by the smaller roll for gripping the leading end of a paper blank presented to the nip of the rolls, means carried by the larger roll for folding said disk and fingers successively against the small end of said smaller roll, and means carried by said larger roll for operating the gripping means to gripping position when it reaches the nip of the rolls at the beginning of an operating cycle and for operating said gripping means to releasing position after said smaller roll has completed one revolution but before it has completed its second revolution in a cycle of operations.

6. A machine as in claim 5, said folding means consisting of a series of blades secured to the small end of the larger roll and projecting outward from half the circurnference of said small end.

7. A machine as in claim 5, and means carried by the larger said roll operating after the smaller roll has completed its first revolution to punch locking tabs in blank which has been wrapped around the smaller roll to hold sai'd blank in its frusto-conical shape.

8. A machine as in claim 7 for operation on a blank having a tongue of reduced width projecting from the trailing end of the blank, said machine including a lance carried by said larger roll and movable outward therefrom to cut a slit in the blank wrapped on the smaller roll and to tuck the tongue of the blank through the slit.

9. A machine comprising a base, a standard on said base, two hearings on said standard having converging axes, a shaft extending through each said bearing, mutually tangent frusto-conical rolls of unequal size mounted on said shafts, the diameter of the smaller roll at any of the points of mutual contact being half the diameter of the larger roll at the same point, means for driving both rolls simultaneously with the rate of rotation of the smaller roll twice that of the larger roll, a slide extending transversely through said smaller roll, said slide having rack teeth on a side thereof and a gripper jaw at an end thereof movable with said slide to project outward beyond the contour of the roll, a gripper shaft extending longitudinally within said smaller roll, a pinion on said gripper shaft meshing with said rack teeth within the roll, a second pinion on said gripper shaft, a spring detent engaging said second pinion to hold said gripper shaft releasably against rotation, a second rack carried by said smaller roll in mesh with said second pinion, and means carried by the larger roll for pressing the gripper jaw inward when the larger roll reaches a predetermined angular position, and means carried by the larger roll to engage said second rack and cause said gripper jaw to move outward when the larger roll reaches another predetermined angular position.

10. A machine for forming arcuate blanks with end tabs into paper cups with tapering side walls, said machine comprising a base, two mutually tangent rolls having side walls with the same angle of taper as said cups rotatably mounted on said base, means for driving said rolls at equal peripheral speeds, means on one said roll for gripping the leading edge of a blank whereby to wrap the blank thereabout, and means for tucking the end tab of said blank through the convolution of the blank previously wrapped about said one roll, said tucking means comprising a plunger reciprocable within the other said roll in a transverse direction, a lance mounted on said plunger and movable thereby from a position within said other roll to project out beyond the side wall of said other roll,

said one roll having a recess therein located to receive the projected lance, and means for reciprocating said plunger and lance in timed relation to the rotation of said rolls.

1]. A machine for forming arcuate blanks with end tabs into paper cups with tapering side Walls, said machine comprising a base, two mutually tangent rolls having side walls with the same angle of taper as said cups rotatably mounted on said base, means for driving said rolls at equal peripheral speeds, means on one said roll for gripping the leading edge of a blank, whereby to Wrap the blank thereabout, means for forming interlock tongues by punching through two plies of said blank Where the trailing end thereof overlaps the leading end, said punching means comprising a plunger reciprocable within the 15 2,049,417

other said roll in a transverse direction and a punch mounted on said plunger and movable thereby from a position Within said other roll to project out beyond the side wall thereof, said one roll having a recess or female portion of a die conforming to the contour of the said punch, and means for reciprocating said plunger and punch in timed relation to the rotation of said rolls.

References Cited in the file of this patent UNITED STATES PATENTS 448,143 Piper Mar. 10, 1891 914,578 Johnston Mar. 9, 1909 1,495,040 Potts May 20, 1924 Barbieri Aug. 4, 1936 

